Exemplary embodiments generally pertain to the field of electric power generating systems (EPGS), and more particularly to high voltage direct current (DC) power generation with active voltage ripple compensation.
Generally, a conventional DC power generating system utilizes a variable-speed permanent magnet synchronous generator (PMG) and an active rectifier. PMG typically offers high efficiency and high power density in comparison with a wound-field synchronous generator construction. However, the size of the conventional 2-level six switching device active rectifier often requires large size passive components, such as electromagnetic interference (EMI) filters, DC link capacitor(s) and output power quality filter(s). To achieve a high power density multilevel topologies, such as Vienna Rectifier, have been considered to achieve low harmonic distortion with moderate switching frequency and reduced EMI emissions compared to a standard 2-level active rectifier/inverter. However, this approach may require the use of custom SiC power modules resulting in a higher system cost. Another approach is to use a conventional six-pulse passive rectifier coupled with a DC-DC boost converter. This approach, however, typically exhibits a large voltage ripple at 6-times of PMG fundamental frequency. In many applications such voltage ripple may be considered objectionable. To that end, there is a need for a high voltage (270Vdc) mid (˜10 kW) power generating system employing a PMG and a high frequency power converter into an affordable high power density alternator that exhibits good power quality.